Operator protection apparatus with an over-center linkage

ABSTRACT

Aspects hereof relate to an operator protection apparatus having at least one over-center linkage. In some aspects, an operator protection apparatus can be raised and lowered by an operator from a seated position, for example, on a terrain working vehicle. Additionally, the at least one over-center linkage may automatically lock in the operator protection apparatus in a raised position. Accordingly, a mechanical force is then required to overcome the lock, and allow the operator protection apparatus to return to a lowered position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 15/041,718, filed Feb. 11, 2016, and entitled “Operator ProtectionApparatus with an Over-Center Linkage.” U.S. application Ser. No.15/041,718 claims the benefit of U.S. Provisional Application No.62/115,868, filed Feb. 13, 2015 and entitled “Rollover ProtectionApparatus with an Over-center Mechanism.” The entirety of theaforementioned applications is incorporated by reference herein.

FIELD

Aspects provided relate to an operator protection apparatus forvehicles. More particularly, aspects herein relate to an operatorprotection apparatus having an over-center linkage that moves from araised position to a lowered position and is suitable for use on anumber of vehicles, including terrain working vehicles.

BACKGROUND

Some operator or operator protection apparatuses for terrain workingvehicles may have a fold-down capability for avoiding overheadobstacles. Traditionally, foldable operator protection apparatuses haveincluded a lower portion in a fixed position and an upper portion thatis mounted to the lower portion. Further, many foldable operatorprotection apparatuses require that an operator manually actuate theupper portion between a raised and a lowered position, which may requirethat the operator leave the seating platform of the vehicle.Resultantly, efficiencies in the operation performed by the operator andmay be reduced.

Additionally, previous foldable operator protection apparatuses haveused bulky securing devices to secure the upper portion in a raisedposition. Various securing devices, such as removable pins and the like,have been employed to secure upper portions in a raised position.Further, as can be appreciated, removable securing devices may be lostor misplaced, further decreasing efficiencies of the operator duringoperations.

SUMMARY

Aspects hereof relate to an operator protection apparatus that can belowered and raised to a locked position using at least one over-centerlinkage. The operator protection apparatus includes a lower portion andan upper portion that is movable relative to the lower portion. Theupper portion may be coupled to the lower portion with one or more hingejoints. Additionally, the at least one over-center linkage may bepivotably coupled to the upper portion and the lower portion. In someaspects, the over-center linkage includes a lower link assembly and anupper link assembly coupled at a center pivot joint. Additionally, theover-center linkage may be configured to move between the lockedposition and an unlocked position. When the over-center linkage is inthe locked position, the over-center linkage may retain the upperportion in the raised position. Further, the apparatus may include anactuator coupled to the over-center linkage for moving the apparatusbetween the locked and/or raised position and the unlocked and/or orlowered position.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Illustrative embodiments of the present invention are described indetail below with reference to the attached drawing figures, which areincorporated by reference herein and wherein:

FIG. 1 depicts a riding mower having an operator protection apparatusaffixed thereto in a raised position, in accordance with aspects hereof;

FIG. 2 depicts a perspective view of an operator protection apparatushaving an over-center linkage in a raised position, in accordance withaspects hereof;

FIG. 3 depicts a side view of the operator protection apparatus of FIG.2 in the raised position, in accordance with aspects hereof;

FIG. 4 depicts a side view of the operator protection apparatus of FIG.2 in a top dead center position, in accordance with aspects hereof;

FIG. 5 depicts a perspective view of the operator protection apparatusof FIG. 2 in a lowered position, in accordance with aspects hereof;

FIG. 6 depicts a perspective view of an exemplary powered actuator, inaccordance with aspects hereof;

FIG. 7 depicts a perspective view of an exemplary electric-hydraulicactuator, in accordance with aspects hereof;

FIG. 8 depicts a perspective view of an exemplary electric actuator, inaccordance with aspects hereof;

FIG. 9 depicts a perspective view of an mechanical actuator, inaccordance with aspects hereof:

FIG. 10 depicts a perspective view of an operator protection apparatushaving two over-center linkages in a raised position, in accordance withaspects hereof;

FIG. 11 depicts a perspective of the operator protection apparatus ofFIG. 10 in a lowered position, in accordance with aspects hereof;

FIG. 12 depicts a perspective view of an operator protection apparatuswith an assist in a raised position, in accordance with aspects hereof;

FIG. 13 depicts an alternative perspective view of an operatorprotection apparatus in a raised position, in accordance with aspectshereof;

FIG. 13 depicts an alternative perspective view of an operatorprotection apparatus in a raised position, in accordance with aspectshereof;

FIG. 14 depicts an alternative perspective view of an operatorprotection apparatus in a raised position, in accordance with aspectshereof;

FIG. 15 depicts a riding mower having an operator protection apparatusaffixed thereto in a raised position, in accordance with aspects hereof;

FIG. 16 depicts a perspective view of the operator protection apparatusof FIG. 15 in a raised position, in accordance with aspects hereof;

FIG. 17 depicts a perspective view of the operator protection apparatusof FIG. 15 in a lowered position, in accordance with aspects hereof; and

FIG. 18 depicts a riding mower having an alternative operator protectionapparatus affixed thereto in a raised position, in accordance withaspects hereof.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is describedwith specificity herein to meet statutory requirements. However, thedescription itself is not intended to limit the scope of this patent.Rather, the inventors have contemplated that the claimed subject mattermight also be embodied in other ways, to include different steps orcombinations of steps similar to the ones described in this document, inconjunction with other present or future technologies.

Aspects hereof relate to an operator protection apparatus that can beraised and lowered by an operator in a seated position, for example, ona riding mower. Additionally, the operator protection apparatus may lockin the raised position. The movement and locking may be facilitated byan over-center linkage. For example, when an operator raises an upperportion of the operator protection apparatus, a center pivot joint ofthe over-center linkage may be configured to move to a position past acenterline defined as extending between pivots points at opposing endsof the linkage. Accordingly, a mechanical force is then required toovercome the lock and allow the operator protection apparatus to returnto a lowered position.

As a result, an operator may lower the upper portion of the operatorprotection apparatus, for example to avoid an obstacle, without stoppingoperation or leaving an operator seat of the vehicle. As can beappreciated, the convenience and ease of use of the operator protectionapparatuses described herein may be conducive to improving the frequencyof use of the operator protection apparatus. Further, the over-centerlinkage may provide a securing device that remains attached to theoperator protection apparatus. Accordingly, the operator protectionapparatuses provided herein may be secured in the raised and/or lockedposition using a securing device without loose parts. As a result, theapparatuses provided herein may eliminate the need for removablesecuring mechanisms, which if detached and misplaced, may causeinefficiencies during the operation of a vehicle associated with theoperator protection apparatus.

A first exemplary embodiment provides for an operator protectionapparatus, the apparatus comprising a lower portion and an upperportion. The lower portion may have a first end and a second end and theupper portion may also have a first end and a second end. The apparatusmay also include at least one hinge joint (e.g., pivot) coupling thelower portion second end to the upper portion first end such that theupper portion is movable relative to the lower portion. Stateddifferently, the upper portion may be pivotably coupled with the lowerportion. Further, in some aspects, the apparatus comprises at least oneover-center linkage effective to lock the upper portion in a setposition (e.g., raised) relative to the lower portion. The over-centerlinkage comprises a lower link assembly having a first end and a secondend, the first end is pivotably coupled to the lower portion at a lowerpivot joint. The over-center linkage further comprises an upper linkassembly having a first end and a second end, the upper link assemblyfirst end is pivotably coupled to the lower link assembly second endforming a center pivot joint, and the upper link assembly second end ispivotably coupled with the upper portion at an upper pivot joint.Accordingly, the over-center linkage is in a locked position when thecenter pivot joint is on a first side of a line extending between thelower pivot joint and the upper pivot joint and the center pivot jointis in an unlocked position on a second side of the line. The apparatusmay also include at least one actuator coupled to the over-centerlinkage.

A second exemplary embodiment provides for an operator protectionapparatus for a terrain working vehicle. The operator protectionapparatus may comprise a lower portion having a first end and a secondend, wherein the first end is affixed to a frame of the terrain workingvehicle; an upper portion having a first end and a second end; and atleast one hinge joint coupling the lower portion second end to the upperportion first end such that the upper portion is movable relative to thelower portion. The operator protection apparatus may include at leastone over-center linkage, the at least one over-center linkagecomprising: a lower link assembly having a first end and a second end,the first end pivotably coupled to the lower portion at a lower pivotjoint; an upper link assembly having a first end and a second end, theupper link assembly first end pivotably coupled to the lower linkassembly second end forming a center pivot joint, and the upper linkassembly second end pivotably coupled with the upper portion at an upperpivot joint. In one aspect, the over-center linkage is in a lockedposition when the center pivot joint is on a first side of a lineextending between the lower pivot joint and the upper pivot joint andthe center pivot joint is in an unlocked position on a second side ofthe line. The operator protection apparatus may also include at leastone actuator coupled to the over-center linkage.

Yet another exemplary embodiment provides for a riding mower having anoperator protection apparatus. The riding mower may comprise a frame; amower deck coupled to the frame; and an operator protection apparatus.The apparatus may comprise: a lower portion comprising a first lowerportion upright having a first upright first end and a first uprightsecond end, and a second lower portion upright having a second uprightfirst end and a second upright second end. The apparatus mayadditionally comprise an upper portion comprising a first upper portionmember having a first member first end and a first member second end, asecond upper portion member having a second member first end and asecond member second end, and a transverse member disposed between thefirst member second end and the second member second end. The apparatusmay also include a pair of hinge joints coupling the first uprightsecond end to the first member first end and the second upright secondend to the second member first end such that the upper portion ismovable relative to the lower portion. Further, the apparatus comprisesa first over-center linkage, the first over-center linkage comprising: afirst lower link assembly having a first lower link first end and afirst lower link second end, wherein the first lower link first end ispivotably coupled to the first lower portion upright at a first lowerlink pivot joint; a first upper link assembly having a first upper linkfirst end and a first upper link second end, wherein the first upperlink assembly first end is pivotably coupled to the first lower linkassembly second end at a first center pivot joint. In one aspect, thefirst over-center linkage is in a locked position when the first centerpivot joint is on a first side of a first line extending between thefirst lower link pivot joint and the first upper link pivot joint, andthe first over-center linkage is in an unlocked position when the firstcenter pivot joint is on a second side of the first line. The operatorprotection apparatus may also include a first actuator coupled to thefirst over-center linkage at a first actuator-over-center pivot jointand coupled to the first lower portion upright at a firstactuator-upright pivot joint for moving the upper portion between lockedposition and the unlocked position. The riding mower may also include acontroller for controlling one or more operations of the riding mower;and one or more sensors communicatively coupled to the controller.

FIG. 1 depicts an exemplary aspect of an operator protection apparatus100 mounted on a riding mower 190, in accordance with aspects hereof. Insome aspects, the riding mower may include a mower deck 191 coupled tothe frame 192 and a controller 198. The riding mower 190 may alsocomprise a frame 192 having a frame first end 194 and a frame second end196. In one aspect herein, a horizontal line 1-1 extending from theframe first end 194 to the frame second end 196 defines a horizontalplane, which may be referred to herein in order to describe locationsand positions of various components of the operator protectionapparatuses described herein. The mower 190 of FIG. 1 is exemplary innature. It is contemplated that the operator protection apparatus ofprovided herein may be associated with any vehicle having an occupant.Nonlimiting examples of vehicles with which the operator protectionapparatus may be associated include terrain working vehicles, lawntractors, UTVs, ATVs, compact tractors, and loaders.

The operator protection apparatus 100 may include a lower portion 102and an upper portion 110. In some aspects, the lower portion 102 maycomprise a pair of mirror-image lower portion 102 uprights. Accordingly,the lower portion 102 may be described herein as comprising the pair oflower portion 102 uprights. The lower portion 102 may be affixed to orintegrally formed with a frame of any number of vehicles. Similarly, theupper portion 110 may include a pair of mirror-image upper portionmembers and a transverse member affixed between the upper portionmembers. Accordingly, the upper portion 110 may be described herein ascomprising the upper portion members and the transverse member. However,as will be provided hereinafter, alternative configurations arecontemplated while achieving the aspects provided for the operatorprotection apparatus 100.

Further, the operator protection apparatus 100 may comprise at least onehinge joint 120 for coupling the lower portion 102 to the upper portion110 and at least one over-center linkage 140. The over-center linkage140 may be pivotably coupled to the lower portion 102 and the upperportion 110. Further, the over-center linkage 140 may be movable betweena locked and an unlocked position. In one example, when in the lockedposition, the over-center linkage 140 may provide a mechanical stop toprevent back-driving of the operator protection apparatus 100, in orderto keep the operator protection apparatus 100 in a raised position.

FIG. 2 depicts a perspective view of one embodiment of the operatorprotection apparatus 100 having at least one over-center linkage 140, inaccordance with aspects hereof. The operator protection apparatus 100may include a lower portion 102 and an upper portion 110. Additionally,the operator protection apparatus 100 may include at least oneover-center linkage 140. In some aspects, the over-center linkage 140may include a lower link assembly 142 pivotably coupled to the lowerportion 102 at a lower pivot joint 148. Further, the over-center linkage140 may include an upper link assembly 150 pivotably coupled to thelower link assembly 142 at a center pivot joint 156. Additionally, theupper link assembly 150 may be pivotably coupled with the upper portion110 at an upper pivot joint 158. Any of the links, members, or otherelements may be adjustable in orientation and/or length to achieveaspects provided herein. For example, the upper link assembly 150 may bean opposing threaded screw link allowing for a rotational movement toadjust the length of the link.

Further, the operator protection apparatus 100 may include a stop lug155 for limiting movement of the over-center linkage 140 beyond thelocked position. In one aspect, the stop lug 155 may be affixed to thelower portion 102 (for example via a bracket) such that the lower linkassembly 142 contacts the stop lug 155 when the over-center linkage 140is in the locked position. In other aspects, the stop lug 155 may beaffixed to the upper portion 110. The stop lug 155 is one example of amechanism for limiting movement of the over-center linkage 140 beyondthe locked position. Other structures and mechanisms for limitingmovement of the over-center linkage 140 may also be employed. In anadditional aspect, the stop lug 155, or other stopping mechanism, may beassociated with the over-center linkage 140. For example, the stop lug155 may be affixed to the over-center linkage 140 such that the stop lug155 contacts the surface of the lower portion 102 and/or the upperportion 110. Additionally, one or more pivot joints associated with theover-center linkage 140 (for example, lower pivot joint 148, upper pivotjoint 158, and center pivot joint 156) may be limited pivot joints, suchthat the joints include a limiter for limiting rotation past the lockedposition.

Additionally, the operator protection apparatus 100 may include at leastone actuator 122 coupled to the over-center linkage 140. The actuator122 may generally operate to articulate the over-center linkage 140between the locked position and the unlocked position. In some aspects,once the actuator 122 has moved the over-center linkage 140 to theunlocked position, the actuator 122 may provide a force required to movethe upper portion 110 to the lowered position and return the upperportion 110 to the a raised and/or locked position. Although shown hereas a hand lever 124, the actuator 122 may be a powered actuator, such asan electric, pneumatic, hydraulic, or mechanical actuator. Severalexamples of actuators are described below, however any suitablemechanism for performing the actuation is considered within the scope ofthis disclosure.

Additionally, the apparatus may comprise at least one securing device130 associated with the over-center linkage 140 and permanently affixedto the apparatus. In one aspect, the securing device 130 may include aprojection for engaging a securing device engagement aperture 121 of thehand lever 124. In one example, the projection may be spring-loaded,such that when the projection is aligned with a securing deviceengagement aperture 121, the hand lever 124 is secured. Further, thesecuring device 130 may include a sensor for detecting an engagement ofthe securing device 130. In some aspects, the sensor may be integratedwith the securing device 130, or may be associated with the securingdevice 130. Any number of securing devices may be suitable for securingthe actuator 122. At a high level, the securing device 130 retains theactuator 122, such that the actuator 122 ensures the over-center linkage140 remains in the locked position.

In one aspect, the operator protection apparatus 100 includes a positionsensor 170. The position sensor 170 may be configured to detect one ormore positions of the operator protection apparatus 100. For example,the sensor may be configured to detect when the operator protectionapparatus 100 is in a locked position. In additional aspects, theposition sensor 170 may be detect when the operator protection apparatus100 is in the raised position, but is not in the locked position. In oneaspect, a position sensor 170 may include a projection that is depressedwhen the over-center linkage 140 is in the locked position. Further, insome aspects of the position sensor 170 may be configured to communicatethe one or more positions, for example to a controller 198 (described inmore detail below). Accordingly, a time that the operator protectionapparatus 100 is in each position of the one or more positions may bedetermined using the sensed information detected by the position sensor170.

As shown in FIG. 3, the lower portion 102 may comprise a lower portionfirst end 104 and a lower portion second end 106. The lower portionfirst end 104 may be welded to (or fastened using any number of means),or may be integrally formed with a frame of a vehicle. Accordingly, theterm “end,” as used herein, does not necessarily indicate a point atwhich a given component terminates. For example, the lower portion firstend 104 may be contiguous with the frame of the vehicle. The upperportion 110 may include an upper portion first end 112 and an upperportion second end 114. The operator protection apparatus 100 may alsoinclude at least one hinge joint 120, as described above. In one aspect,the at least one hinge joint 120 may couple the lower portion second end106 to the upper portion first end 112, such that the upper portion 110is movable relative to the lower portion 102.

The over-center linkage 140 may include the lower link assembly 142having a lower link first end 144 and a lower link second end 146. Thelower link first end may be pivotably coupled to the lower portion 102at the lower pivot joint 148. Further, the over-center linkage 140 mayinclude an upper link assembly 150 having an upper link first end 152and an upper link second end 154. The upper link first end 152 may bepivotably coupled to the lower link second end 146 to form a centerpivot joint 156. Additionally, the upper link assembly second end may bepivotably coupled with the upper portion 110 at an upper pivot joint158.

Turning now to more particular aspects, the over-center linkage 140 mayinclude a centerline 2-1 extending between the lower pivot joint 148 andthe upper pivot joint 158. The centerline 2-1 may include a first side2A and a second side 2B. The over-center linkage 140 may be in a lockedposition when the center pivot joint 156 is on the first side 2-1 ofcenterline 2-1. Accordingly, the over-center linkage 140 may be in anunlocked position (as shown in FIG. 5) when the center pivot joint 156is on the second side 2B of the centerline 2-1. As can be appreciated,in alternative configurations the over-center linkage 140 may beoriented and positioned such that the over-center linkage 140 isconfigured to be in the locked position in a variety of directions. Suchalternative configurations are considered within the scope of thisdisclosure.

Further, when the over-center linkage 140 is in the locked position, theover-center linkage 140 may provide a mechanical stop to preventback-driving of the mechanism. In some aspects, the movement of thecenter pivot joint 156 in the direction of the first side may belimited, for example, such by the stop lug 155. In other aspects, thecenter pivot joint 156 may be limited by the lower portion 102 and theupper portion 110, or by a center pivot joint 156 that limits rotationin the direction of the first side.

The operator protection apparatus 100 may be described as having amidline 3-1. The midline 3-1 of the operator protection apparatus 100may have a first midline line segment 3-2 extending from the lowerportion first end 104 to the hinge joint 120 and a second midline linesegment 3-3 extending from the hinge joint 120 to the upper portionsecond end 114. Accordingly, the midline 3-1 may define a midline firstside 3A and a midline second side 3B. Further, a lower portion ray 4-1may extend from the lower portion first end 104 through the hinge joint120. Said another way, the lower portion ray 4-1 may be an extension offirst midline line segment 3-2. Further, the lower portion ray 4-1 mayhave a lower portion ray first side 4A and a lower portion ray secondside 4B. Accordingly, the operator protection apparatus 100 may bedescribed as having first side 116 and a second side 118 opposite thefront side 116. The first side 116 of the operator protection apparatus100 may be oriented in the same direction as midline first side 3A, andthe second side 118 may be oriented in the same direction as midlinesecond side 3B.

In some aspects, the operator protection apparatus 100 may include astop 134 associated with at least one of the upper portion 110 and thelower portion 102. The stop 134 limits a range of motion of the upperportion 110 in a radial direction toward the lower portion ray firstside 4A. The stop 134 may be affixed to the operator protectionapparatus 100 first side 118 proximate the upper portion second end 114,and extend, at least in part, beyond the upper portion second end 114.Accordingly, when the operator protection apparatus 100 is in a lockedposition, the upper portion may contact the stop 134. In some aspects,the stop 134 may include a bumper 136. The bumper 136 may be anysuitable material for dampening contact forces with the stop 134, suchas a polymer based material. Further, because the range of motion of theupper portion 110 is limited, a range of motion of the center pivotjoint 156 of the over-center linkage 140 may also be limited, forexample, by coming in contact with the lower portion 102 and/or theupper portion 110. Additionally, as discussed hereinabove, the stop lug155, or other mechanism, may limit movement of the over-center linkage140 beyond the locked position.

In some aspects, the lower link assembly 142 may be coupled to the lowerportion 102 by a lower portion bracket 160 and the upper link assembly150 may be coupled to the upper portion 110 by an upper portion bracket162. The lower portion bracket 160 and upper portion bracket 162 may bewelded (or fastened using any number of means), or may be integrallyformed with the upper portion 110 and the lower portion 102. In someaspects, the lower portion bracket 160 and upper portion bracket 162 mayeach be offset from the lower portion 102 and the upper portion 110. Forexample, each of the lower portion bracket 160 and the upper portionbracket 162 may extend outwardly from the second side 118 of theoperator protection apparatus 100. In some aspects, the lower portionbracket 160 may extend further outward from the second side 118 than theupper portion bracket 162. As a result, the lower pivot joint 148 may bepositioned on the lower portion ray second side 4B and the upper pivotjoint 158 may be positioned (at least in part) on the lower portion rayfirst side 4A. Accordingly, the over-center linkage 140 may provide amechanical advantage for retaining the operator protection apparatus 100in a locked position, in that the center pivot joint 156 is biasedtoward the lower portion ray 4-1 when the operator protection apparatus100 is in a raised and/or locked position.

Turning now to FIG. 4, the over-center linkage 140 is shown in a topdead center position, in accordance with aspects hereof. The centerpivot joint 156 may be positioned directly along centerline 2-1 when inthe top dead center position. Said another way, the center pivot joint156 is neither on the first side 2A, nor on the second side 2B of thecenterline 2-1 when in the top dead center position. Accordingly, FIG. 4depicts a break over point, or a point at which the over-center linkage140 is no longer in the locked position. In one example, the over-centerlinkage may be moved to this position by the actuator 122, whichsupplies the force required to overcome the lock provided by theover-center linkage 140.

FIG. 5 depicts the operator protection apparatus 100 in a loweredposition. As shown, the over-center linkage 140 is in the unlockedposition, in that the center pivot joint 156 is on the second side 2B ofthe centerline 2-1. Additionally, the upper portion 110 is positioned onthe lower portion ray second side 4B of lower portion ray 4-1. Asdescribed above, in one aspect, the actuator 122 comprises the handlever 124. The hand lever 124 may include a hand lever pivot joint 123coupled to a hand-lever actuator linkage 126 that extends from the handlever 124 to an actuator-over-center pivot joint 145. Accordingly, ahand lever lower portion 125 may extend from a actuator-lower portionpivot joint 166 to the hand lever pivot joint 123. In some aspects, thehand lever 124 includes a trigger 131 that is configured to disengagethe securing device 130, thereby allowing the operator protectionapparatus 100 to be lowered.

As mentioned above, any number of suitable actuators 340 may be employedin place of or in conjunction with the hand lever 124. For example, asdepicted in FIG. 6, the actuator 122 may comprise a powered actuator240, such as a hydraulic actuator 180. The operator protection apparatus100 may be associated with a vehicle equipped with a hydraulic system.In one aspect, the hydraulic actuator may be powered by the hydraulicsystem of the vehicle. Additionally, as shown in FIG. 7, the actuator122 may be an electric-hydraulic actuator 182. For example, theelectric-hydraulic actuator may include an electric motor 183 that turnsa pump 184. The electric-hydraulic actuator 182 may include a switchthat turns the motor 183 on and off and controls the direction of themotor 183. The direction in which the motor 183 turns may determinewhether a cylinder 181 of the actuator is extended for retracted. Forexample, when the motor 183 turns in a first direction, the pump 184pumps fluid such that the cylinder 181 is extended. Accordingly, whenthe motor 183 turns in a second direction, opposite of the firstdirection, the fluid is pumped in an opposite direction such that thecylinder 181 is retracted.

Further, as shown in FIG. 8, an electric-linear actuator 186 may beimplemented. The electric-linear actuator 186 may include a motor 183that turns a gear reduction set, which turns a screw thread.Accordingly, the cylinder 181 extends and retracts based on whichdirection the motor 183 turns. In an additional aspect, as shown in FIG.9, the actuator may include a mechanical linkage 188. In one example,the mechanical linkage 188 may be connected to a foot pedal 128 (shownin FIG. 1) by a cable 187. The foot pedal 128 may have a first side anda second side that rotate about a pivot such that both sides of the footpedal 128 may be depressed by an operator. In one aspect, when the firstside of the pedal 128 is pushed the cable 187 may be extended, therebyurging the mechanical linkage 188 in a direction that disengages theover-center linkage 140. Accordingly, when the second side of the footpedal 128 is depressed, the cable 187 may be retracted, thereby causingthe mechanical linkage 188 to pull the over-center linkage 140 towardthe raised position.

Turning now to FIG. 10, in another exemplary embodiment, an operatorprotection apparatus 200 having two over-center linkages is depicted.The operator protection apparatus 200 may include a lower portion 201comprising a first lower portion upright 201 and a second lower portionupright 202. The first lower portion upright 201 may have a firstupright first end 203 and a first upright second end 205. The secondlower portion upright 202 may have a second upright first end 204 and asecond upright second end 206. In one aspect, the first upright firstend 203 and the second upright first end 204 may be affixed to a frameof a terrain working vehicle, for example, a riding mower.

Additionally, the upper portion 210 may comprise a first upper portionmember 211 and a second upper portion member 212. The first upperportion member 211 may have a first member first end 213 and a firstmember second end 215. The second upper portion member 212 may have asecond member first end 214 and a second member second end 216. Further,the upper portion 210 may comprise a transverse member 217 disposedbetween the first member second end 215 and the second member second end216. While the first upper portion member 211 and the second upperportion member 212 are discussed as distinct members, it is contemplatedthat they form a continuous and contiguous assembly as a commoncomponent or assembly. Further, the operator protection apparatus mayhave a pair of hinge joints 120 coupling the first upright second end205 to the first member first end 213 and the second upright second end206 to the second member first end 214, such that the upper portion 210is movable relative to the lower portion 201.

Additionally, in some aspects, the operator protection apparatus 200 mayinclude a first over-center linkage 220. The first over-center linkage220 may comprise a first lower link assembly 221 having a first lowerlink first end 222 and a first lower link second end 223. The firstlower link first end 222 may be pivotably coupled to the first lowerportion upright 201 at a first lower link pivot joint 224. The firstover-center linkage 220 may also comprise a first upper link assembly225 having a first upper link first end 226 and a first upper linksecond end 227. The first upper link assembly 225 first end may bepivotably coupled to the first lower link second end 223 at a firstcenter pivot joint 228. Further, the first upper link second end 227 maybe pivotably coupled to the first upper portion member 211 at a firstupper pivot joint 229.

Further, in some aspects, the operator protection apparatus 200comprises a second over-center linkage 230. The second over-centerlinkage 230 may comprise a second lower link assembly 231 having asecond lower link first end 232 and a second lower link second end 233.The second lower link first end 232 may be pivotably coupled to thesecond lower portion upright 202 at a second lower link pivot joint 234.The second over-center linkage 230 may also comprise a second upper linkassembly 235 having a second upper link first end 236 and a second upperlink second end 237. The second upper link assembly 235 first end may bepivotably coupled to the second lower link second end 233 at a secondcenter pivot joint 238. Further, the second upper link second end 237may be pivotably coupled with the second upper portion member 212 at asecond upper pivot joint 239.

Similar to the over-center linkage 140 described hereinabove, the firstover-center linkage 220 may be in a locked position when the firstcenter pivot joint 228 is on a first centerline first side 200A of afirst centerline 200-1 extending between the first lower link pivotjoint 224 and the first upper link pivot joint 229. Accordingly, thesecond over-center linkage 230 may be in a locked position when thesecond center pivot joint 238 is on a second centerline first side 210Aof a second centerline 210-1 extending between the second lower linkpivot joint 234 and the second upper pivot joint 239.

In one aspect, the operator protection apparatus 200 comprises a firstactuator 240 for moving the first over-center linkage 220 between thelocked position and an unlocked position. The first actuator 240 may becoupled to the first over-center linkage 220 at a firstactuator-over-center pivot joint 242 and coupled to the lower portion201 of the upright at a first actuator-upright pivot joint 244. In someaspects, the apparatus includes a torque tube 250 (which may be referredto as a rod) affixed between the over-center linkages 220 and 230. Thetorque tube 250 may transfer the rotational force supplied by theactuator 240 from the first over-center linkage 220 to the secondover-center linkage 230. As a result, the second over-center linkage 230may be moved from the locked position to the unlocked positionsimultaneously with the first over-center linkage 220.

FIG. 11 depicts the operator protection apparatus 200 and anunlocked/lowered position, in accordance with aspects hereof. The firstover-center linkage 220 may be in the unlocked position when the firstcenter pivot joint 228 on a first centerline second side 200B of thefirst centerline 200-1. Accordingly, the second over-center linkage 230is in the unlocked position when the second center pivot joint 238 on asecond centerline second side 210B of the second centerline 210-1.

Turning now to FIG. 12, in one aspect, the operator protection apparatus200 may comprise a gas cylinder 245 coupled to the second over-centerlinkage 230 at a second actuator-over-center pivot joint 246 and coupledto the second lower portion upright 202 at a second actuator-uprightpivot joint 248, in accordance with aspects hereof. The gas cylinder 245may function as a biasing mechanism or an assist for retaining thesecond over-center linkage 230 in the locked position. Additionally, thegas cylinder 245 may support and/or compensate for the weight of theupper portion 210 as the upper portion 210 rotates from the raisedposition to the lowered position. Although shown as a gas cylinder 245in FIG. 12, other suitable mechanisms (e.g., coil spring, torsionspring, torsion bar) are considered within the scope of this disclosure.

Further, as shown in FIG. 13, the operator protection apparatus 200 mayimplement a powered actuator 240 in place of or in conjunction with anyof the actuators contemplated herein. In a nonlimiting example, thepowered actuator may be a linear actuator and may be electric,pneumatic, or hydraulic. In some aspects, the powered actuator may becoupled to the first over-center linkage 220 at a firstactuator-over-center pivot joint 242 and coupled to the first lowerportion upright 201 at a first actuator-upright pivot joint 244. In someaspects, the force provided by the powered actuator may apply a force tosecure the operator protection apparatus 200 in the locked position.

Additionally, as shown in FIG. 14, the operator protection apparatus 200may include a handle 280. The handle 280 may be affixed to the torquetube 250 and positioned such that the handle 280 engages a securingdevice 130 when the second over-center linkage 230 is in a lockedposition. Accordingly, the handle 280 may be disengaged from thesecuring device 130, thereby allowing the over-center linkage to theunlocked and the upper portion to be lowered. As can be appreciated, anyof the actuators provided herein may be included on the operatorprotection apparatus 200 with the handle 280.

With reference now to FIG. 15, in yet another embodiment, an operatorprotection apparatus 300 having two powered actuators is provided.Accordingly, a first powered actuator 340 and a second powered actuator345 may be configured to actuate simultaneously and with equal (ordifferent) force. As depicted in FIG. 15, the operator protectionapparatus 300 may be affixed to a frame 192 of a vehicle, such as frame392 of riding mower 390. In some aspects, the riding mower 190 mayinclude a mower deck 391 coupled to the frame 392 and a controller 398.Further, the riding mower 390 may include a seat 393. The frame 392 mayinclude a frame first end 394 and a frame second end 396. In one aspectherein, a horizontal line 390-1 extending from the frame first end 394to the frame second end 396 defines a horizontal plane, which may bereferred to herein in order to describe locations and positions ofvarious components of the operator protection apparatus 300.

The operator protection apparatus 300 may include a lower portion 301comprising a first lower portion upright 303 and a second lower portionupright 302. Additionally, an upper portion 310 may comprise atransverse member 317 disposed between a first upper portion member 311and a second upper portion member 312. Further, the operator protectionapparatus may have a pair of hinge joints 120 coupling the first lowerportion upright 303 to the first upper portion member 311 and the secondlower portion upright 302 to the second upper portion member 312, suchthat the upper portion 310 is movable relative to the lower portion 301.

Additionally, in some aspects, the operator protection apparatus mayinclude a first over-center linkage 320 and a second over-center linkage330. The first over-center linkage 320 may be coupled to the first lowerportion upright 303 and the first upper portion member 311, and thesecond over-center linkage 330 may be coupled to the second lowerportion upright 302 and the second upper portion member 312.

The first powered actuator 340 may be coupled to the first lower portionupright 303 and the first over-center linkage 320. Further, the secondpowered actuator 345 may be coupled to the second lower portion upright302 and the second over-center linkage 330. The operator protectionapparatus 300 may include at least one input device for controlling thepowered actuators 340 and 345. The input device is configured to controlactuation of the powered actuators 340 and 345 simultaneously, asmentioned above. In some aspects, the input device may be a simpleswitch communicatively coupled directly to the powered actuators 340 and345. In other aspects, the input device may be communicatively coupledto the controller 398, which may control the powered actuators 340 and345.

In one aspect, the input device may be a foot button 341 that may bedepressed by the foot of an operator to initiate actuation for bothraising and lowering the upper portion 310. In another aspect, the inputdevice may be a toggle switch 343. For example, holding the toggleswitch 343 in a first direction may cause the actuators to lower theupper portion 310 until the switch is released. Additionally, holdingthe toggle switch 343 in a second direction may cause the actuators 340and 345 to raise the upper portion 310. Alternatively, momentarilymoving the toggle switch 343 in the second direction, rather thanholding the toggle switch 343, may cause the actuators 340 and 345 toraise the upper portion to the locked position. Although described inthe examples above, the input device may be implemented as any othersuitable type of input device and at any other suitable location. Forexample, the input device may be associated with operator controls 395such that the operator protection apparatus 300 may be controlled by anoperator while the operator is using the operator controls 395.

Turning now to FIG. 16, the first lower portion upright 303 may have afirst upright first end 305 and a first upright second end 307. Thesecond lower portion upright 302 may have a second upright first end 304and a second upright second end 306. In one aspect, the first uprightfirst end 305 and the second upright first end 304 may be affixed to aframe of a terrain working vehicle (for example riding mower 390). Thefirst upper portion member 311 may have a first member first end 313 anda first member second end 315. The second upper portion member 312 mayhave a second member first end 314 and a second member second end 316.

The first over-center linkage 320 may comprise a first lower linkassembly 321 having a first lower link first end 322 and a first lowerlink second end 323. The first lower link first end 322 may be pivotablycoupled to the first lower portion upright 303 at a first lower linkpivot joint 324. The first over-center linkage 320 may also comprise afirst upper link assembly 325 having a first upper link first end 326and a first upper link second end 327. The first upper link assembly 325first end may be pivotably coupled to the first lower link second end323 at a first center pivot joint 328. Further, the first upper linksecond end 327 may be pivotably coupled with the first upper portionmember 311 at a first upper pivot joint 329. In one aspect, the firstpowered actuator 340 is coupled to the first over-center linkage 320 ata first actuator-over-center pivot joint 342 and coupled to the firstlower portion upright 303 at a first actuator-upright pivot joint 344.

The operator protection apparatus 300 may comprise a second over-centerlinkage 330. The second over-center linkage 330 may comprise a secondlower link assembly 331 having a second lower link first end 332 and asecond lower link second end 333. The second lower link first end 332may be pivotably coupled to the second lower portion upright 302 at asecond lower link pivot joint 334. The second over-center linkage 330may also comprise a second upper link assembly 335 having a second upperlink first end 336 and a second upper link second end 337. The secondupper link assembly 335 first end may be pivotably coupled to the secondlower link second end 333 at a second center pivot joint 338. Further,the second upper link second end 337 may be pivotably coupled with thesecond upper portion member 312 at a second upper pivot joint 339. Thesecond powered actuator 345 may be coupled to the second over-centerlinkage 330 at a second actuator-over-center pivot joint 346 and coupledto the second lower portion upright 302 at a second actuator-uprightpivot joint 348.

The first over-center linkage 320 may be in a locked position when thefirst center pivot joint 328 is on a first centerline first side 300A ofa first centerline 300-1 extending between the first lower link pivotjoint 324 and the first upper pivot joint 329. The second over-centerlinkage 330 may be in a locked position when the second center pivotjoint 338 is on a second centerline first side 310A of a secondcenterline 310-1 extending between the second lower link pivot joint 334and the second upper pivot joint 339.

Turning now to FIG. 17, the first over-center linkage 320 may be in anunlocked position when the first center pivot joint 328 is on a firstcenterline second side 300B of the first centerline 300-1. Accordingly,the second over-center linkage 330 is in an unlocked position when thesecond center pivot joint 338 is on a second centerline second side 310Bof the second centerline 310-1. Additionally, similar to the embodimentsdescribed hereinabove, the operator protection apparatus 300 may includeone or more stops 350 that limit a range of motion of the upper portion310 relative to the lower portion 301. Further, the operator protectionapparatus 300 may include a pair of lower portion brackets 352 and apair of upper portion brackets 354 for coupling the first over-centerlinkage 320 and the second over-center linkage 330 to the lower portion301 and the upper portion 310.

In an additional embodiment, as depicted in FIG. 18, an operatorprotection apparatus 400 may be affixed to a frame of a vehicle, such asframe 492 of riding mower 490. In some aspects, the riding mower mayinclude a mower deck 491 coupled to the frame 492 and a controller 498.Further, the riding mower 490 may include a seat 493. The riding mowermay comprise, a frame 492 having a frame first end 494 and a framesecond end 496. In one aspect herein, a horizontal line 490-1 extendingfrom the frame first end 494 to the frame second end 496 defines ahorizontal plane, which may be referred to herein in order to describelocations and positions of various components of the operator protectionapparatus 400.

The operator protection apparatus 400 may include a lower portion 402comprising a lower portion first end 404 and a lower portion second end406. Additionally, the operator protection apparatus 400 may include anupper portion 410 comprising a single upper portion member having anupper portion first end 412 and an upper portion second end 414. Theupper portion 410 may include a cross member 416 affixed to the upperportion second end 414. Further, the operator protection apparatus 400may have a hinge joint 420 coupling the lower portion second end 406 tothe upper portion first end 412, such that the upper portion 410 ismovable relative to the lower portion 402.

Additionally, in some aspects, the operator protection apparatus mayinclude an over-center linkage 440 coupled the lower portion 402 and theupper portion 410. In some aspects, the over-center linkage 440 mayinclude a lower link assembly 442 having a lower link first end 444 anda lower link second end 446 pivotably coupled to the lower portion 402at a lower pivot joint 448. Further, the over-center linkage 440 mayinclude an upper link assembly 450 pivotably coupled to the lower linkassembly 442 at a center pivot joint 456. The lower link first end maybe pivotably coupled to the lower portion 402 at the lower pivot joint448. Additionally, the upper link assembly 450 may be pivotably coupledwith the upper portion 410 at an upper pivot joint 458. The lower linkassembly first end may be pivotably coupled to the lower portion 402 atthe lower pivot joint 448. Further, the over-center linkage 440 mayinclude an upper link assembly 450 having an upper link first end 452and an upper link second end 454. The upper link first end 452 may bepivotably coupled to the lower link second end 446 to at the centerpivot joint 456. Additionally, the upper link assembly second end may bepivotably coupled with the upper portion 410 at an upper pivot joint458.

Additionally, the operator protection apparatus 400 may include anactuator 422 coupled to the lower portion 402 and the over-centerlinkage 440. In one aspect, the actuator may comprise a hand lever 424,although any of the actuators contemplated herein may be used. Forexample, similar to the riding mower depicted in FIG. 1, the ridingmower 490 may include a foot pedal 428. The foot pedal 428 may have afirst side and a second side that rotate about a pivot such that bothsides of the pedal may be pushed by an operator and may be associatedwith a mechanical actuator, as described hereinabove.

The operator protection apparatus 400 may also include a position sensor470. Further, the operator protection apparatus 400 may be coupled toone or more indicators. The one or more indicators may provide a warningor a notification that a position of the operator protection apparatus400 should be changed, or is in an unlocked position. For example, avisual indicator 472, which may be a light, may provide a visualindication that the operator protection apparatus 400 should be in thelocked position. Additionally, one or more tactile indicators 474 may beemployed to notify or warn the operator of a condition related to theoperator protection apparatus 400. Further, the one or more indicatorsmay include an audio indicator (although not shown here, the audioindicator may be associated with the controller 498).

Turning now to a general discussion of each of the embodiments describedhereinabove, a variety of additional features may be implemented witheach of the embodiments. Additionally, some of the features describedhereinabove may include variations, which may be applicable to each ofthe embodiments described herein. For example, although the over-centerlinkages described hereinabove and depicted in the figures may providean advantageous configuration, other configurations should be consideredwithin the scope of this disclosure. For example, it is contemplatedthat an over-center linkage could be positioned such that it is affixedto either an interior surface or an exterior surface of an operatorprotection apparatus.

Additionally, the hinge joints described hereinabove may alternativelybe described as including the over-center linkages. Said another way, ahinge joint that includes an over-center linkage for locking an operatorprotection system has been contemplated and should be considered withinthe scope of this disclosure. Additionally, it should be appreciatedthat the features of the various embodiments described herein may beincorporated with one another.

In another aspect, an operator protection apparatus may be providedwithout an actuator. In one aspect, a grip or other member may extendfrom the a center pivot joint of at least one over-center linkage.Accordingly, the over-center linkage may be unlocked without employingan actuator. In another aspect, a rod may extend between center pivotjoints of two over-center linkages. The rod may be manually movedbetween the locked and unlocked position.

Further, the one or more sensors described hereinabove may include anynumber of sensors associated with a vehicle and/or the operatorprotection apparatus. In some aspects, the operator protection apparatusmay include logic that is integrated with the apparatus or is configuredfor integration with a controller, or other computing device associatedwith the vehicle. Accordingly, an operator protection apparatus mayreceive sensor data from a variety of sensors. For example, a vehiclemay include a tilt sensor configured to detect a tilt of the vehicle,for example in a controller (e.g. controller 198, 298, 398, or 498). Inanother aspect, the tilt sensor may be provided and included with theoperator protection apparatus. Additionally, the operator protectionapparatus may be configured to receive sensor data from a seatbeltsensor associated with the vehicle including, for example, whether theseatbelt is buckled or unbuckled.

The sensed data obtained from different sensors may be used by theoperator protection apparatus logic to make a number of determinations.For example, the sensor data may be used to determine that the operatorprotection apparatus is in a lowered position, and the seatbelt isengaged. In this scenario, the operator protection apparatus may causethe controller to disengage the mower blades. In another aspect, thesensed data may be used to determine that the operator protectionapparatus is in a raised position and the seatbelt is disengaged. Inthis example, similar to the previous scenario, the operator protectionapparatus may communicate a command to the controller to disengage theblades. In additional aspects, the operator protection apparatus mayactivate one or more indicators (e.g., a visual indicator 472 and atactile indicators 474) or warning signals, based on the sensor data.For example, the sensor data may be used to activate audio, visual, ortactile indicators for alerting an operator of the vehicle that a stateof the vehicle or the operator protection apparatus should be changed.

Many different arrangements of the various components depicted, as wellas components not shown, are possible without departing from the spiritand scope of the present invention. Embodiments of the present inventionhave been described with the intent to be illustrative rather thanrestrictive. Alternative embodiments will become apparent to thoseskilled in the art that do not depart from its scope. A skilled artisanmay develop alternative means of implementing the aforementionedimprovements without departing from the scope of the present invention.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations and are contemplated within the scope of the claims. Notall steps listed in the various figures need be carried out in thespecific order described.

What is claimed:
 1. An operator protection apparatus comprising: a lowerportion pivotably coupled to an upper portion at a first pivot jointsuch that the upper portion is movable relative to the lower portionbetween a raised position and a lowered position; and an over-centerlinkage comprising: a lower link movably coupled to the lower portion ata second pivot joint; and an upper link movably coupled to the upperportion at a third pivot joint, the upper link coupled to the lower linkat a fourth pivot joint, wherein the over-center linkage is movablebetween a locked position and an unlocked position.
 2. The operatorprotection apparatus of claim 1, wherein the over-center linkage limitsmovement of the upper portion relative to the lower portion in thelocked position.
 3. The operator protection apparatus of claim 1,wherein the over-center linkage allows movement of the upper portionrelative to the lower portion in the unlocked position.
 4. The operatorprotection apparatus of claim 1, wherein when the over-center linkage isin the locked position, the over-center linkage maintains the upperportion in the raised position.
 5. The operator protection apparatus ofclaim 1, wherein when the over-center linkage is in the unlockedposition, the over-center linkage allows movement of the upper portionto the lowered position.
 6. The operator protection apparatus of claim1, further comprising an actuator coupled to the over-center linkage,the actuator effective to move the over-center linkage between thelocked position and the unlocked position, and effective to move theupper portion between the raised position and the lowered position. 7.The operator protection apparatus of claim 6, wherein the actuatorcomprises one or more of a hand lever and a powered actuator.
 8. Theoperator protection apparatus of claim 1, further comprising a gascylinder coupled with one of the over-center linkage and the upperportion.
 9. An operator protection apparatus for a terrain workingvehicle, the operator protection apparatus comprising: a lower portionconfigured to be coupled with the terrain working vehicle; an upperportion pivotably coupled to the lower portion and movable relative tothe lower portion between a raised position and a lowered position; anover-center linkage pivotably coupled to the lower portion and the upperportion, wherein the over-center linkage is movable between a lockedposition and an unlocked position; one or more sensors coupled with theoperator protection apparatus and associated with the terrain workingvehicle, the one or more sensors configured to generate sensor dataassociated with the operator protection apparatus, the one or moresensors comprising a position sensor configured to detect one or morepositions of the operator protection apparatus; and a controllercommunicatively coupled with the one or more sensors coupled with theoperator protection apparatus.
 10. The operator protection apparatus ofclaim 9, wherein the controller comprises a computing device storinglogic for determining one or more commands based on the sensor dataassociated with the operator protection apparatus.
 11. The operatorprotection apparatus of claim 10, wherein the one or more commandsdetermined by the controller are determined based on terrain workingvehicle sensor data from the one or more sensors associated with theterrain working vehicle.
 12. The operator protection apparatus of claim11, wherein the one or more sensors associated with the terrain workingvehicle comprise a seatbelt sensor.
 13. The operator protectionapparatus of claim 11, wherein the one or more sensors associated withthe terrain working vehicle comprise a tilt sensor.
 14. The operatorprotection apparatus of claim 11, further comprising one or moreindicators for providing an indication in response to the one or morecommands.
 15. The operator protection apparatus of claim 9, furthercomprising a hand lever pivotably coupled to the over-center linkage.16. The operator protection apparatus of claim 15, further comprising ahand-lever actuator linkage pivotably coupled to the hand lever andpivotably coupled to a lower link of the over-center linkage.